Pendleton is located in Umatilla County, Oregon. Pendleton was named in 1868 by the county commissioners for George H. Pendleton, Democratic candidate for Vice-President in the 1864 presidential campaign. The population was 16,612 at the 2010 census. It is the county seat of Umatilla County.

Pendleton is the smaller of the two principal cities of the Pendleton-Hermiston Micropolitan Statistical Area, a micropolitan area that covers Morrow and Umatilla counties and had a combined population of 87,062 at the 2010 census.

The median income for a household in the city was $36,800, and the median income for a family was $47,410. Males had a median income of $31,763 versus $23,858 for females. The per capita income for the city was $17,551. About 8.7% of families and 13.3% of the population were below the poverty line, including 16.4% of those under age 18 and 8.1% of those age 65 or over.